MKSAP quiz: STEMI, heart failure, and diabetes

This month's quiz asks readers to evaluate a 66-year-old man in the hospital following
an ST-elevation myocardial infarction (STEMI) treated with primary percutaneous coronary
intervention.

A 66-year-old man is evaluated in the hospital following ST-elevation myocardial infarction
treated with primary percutaneous coronary intervention of the left anterior descending
artery 4 days ago. His initial presentation was complicated by the presence of heart
failure and pulmonary edema. He is asymptomatic and ambulating, and he is nearly ready
for discharge. Medical history is significant for hyperlipidemia, type 2 diabetes
mellitus, and hypertension. Medications are aspirin, prasugrel, lisinopril, carvedilol,
atorvastatin, and basal and prandial insulin.

On physical examination, vital signs are normal. Oxygen saturation is 99% breathing
ambient air. The remainder of the examination is unremarkable.

MKSAP Answer and Critique

The correct answer is A. Eplerenone. This item is available to MKSAP 18 subscribers
as item 117 in the Cardiovascular Medicine section. More information about MKSAP 18 is available online.

The most appropriate treatment is eplerenone. This patient had an anterior ST-elevation
myocardial infarction (STEMI) complicated by moderate left ventricular (LV) dysfunction
and heart failure. Optimizing this patient's medical therapy is fundamental to preventing
further impairment of LV function and promoting favorable LV remodeling. Although
beta-blockers and angiotensin-converting enzyme (ACE) inhibitors (or angiotensin receptor
blockers [ARBs]) form the backbone of postinfarction medical therapy aimed at preserving
LV function, it is important to recognize when additional agents may be indicated.
The EPHESUS trial established the benefits of aldosterone antagonism with eplerenone
in patients with acute myocardial infarction and concomitant LV dysfunction, and current
guidelines recommend adding an aldosterone antagonist to ACE inhibitor and beta-blocker
therapy in STEMI patients with LV ejection fraction of 40% or less and either heart
failure symptoms or diabetes mellitus. Because of the potassium-sparing effect of
eplerenone, serum potassium levels should be carefully monitored. Eplerenone should
be used with caution in those with underlying kidney disease.

Long-acting nitrates, such as isosorbide mononitrate, have no role in the management
of patients immediately after STEMI. Nitrates may be used for future angina or may
be coupled with hydralazine in those with persistent LV dysfunction despite maximally
tolerated doses of a beta-blocker and ACE inhibitor; however, administering isosorbide
mononitrate is not the most appropriate next step in this patient's management.

Although an ARB such as valsartan may be useful as an alternative to ACE inhibitor
therapy, adding an ARB to a medication regimen that already includes an ACE inhibitor
and beta-blocker has been associated with an excess of adverse events and is therefore
not recommended.

Warfarin therapy is recommended to reduce the risk for systemic embolization in patients
with LV apical clots following large anterior myocardial infarction, although this
recommendation is not based on a large randomized dataset. In this patient, no clots
were noted on the echocardiogram, and empiric anticoagulation is not indicated according
to current guidelines.

Key Point

In patients with STEMI, LV ejection fraction of 40% or less, and either heart failure
symptoms or diabetes mellitus, an aldosterone antagonist is recommended in addition
to ACE inhibitor and beta-blocker therapy.

Internal medicine physicians are specialists who apply scientific knowledge and clinical expertise to the diagnosis, treatment, and compassionate care of adults across the spectrum from health to complex illness. ACP Diabetes Monthly provides a monthly summary for internists about relevant news in diabetes. All published material, which is covered by copyright, represents the views of the contributor and does not reflect the opinion of the American College of Physicians or any other institution unless clearly stated.